Emulsion Polymerization of Dihydroeugenol-, Eugenol-, and Isoeugenol-Derived Methacrylates

International audienc

Synthesis and Self Assembly of Quadruple Hydrogen-Bonded Arrays

The strength and directionality of hydrogen bonds have made them very attractive in the engineering of supramolecular units. This has been translated to the design of multiple hydrogen-bond arrays in order to modify and tune the interaction between supramolecular building blocks. In the present work several bifunctionalized compounds equipped with 7-Amino-1H-[1,8]naphthyridin-2-one as DADA binding unit and a variation of linker moieties by including aromatic groups as benzene and naphthalene, heterocycles as 1,2,3-triazoles, and dendron moieties, by means of reactions as Glaser coupling, Sonogashira coupling and 1,3-dipolar cycloaddition, have been synthesized. Compounds with a dendron structure as linker exhibit adequate solubility in non-polar solvents to execute experiments to study their binding nature. 1H-NMR DOSY experiments suggested that the synthesized dendron compounds were present as dimers and trimers in deuterated dichloromethane

Eugenol: A Promising Building Block for Synthesis of Radically Polymerizable Monomers

International audienceEugenol, a natural phenol currently mainly obtained from clove oil, is an interesting aromatic building block for the synthesis of novel biobased monomers. It can also be obtained from lignin depolymerization, becoming a promising building block due to lignin availability as biomass feedstock. The synthesis of eight monomers derived from eugenol containing polymerizable functional groups is achieved. The (meth)acrylation of eugenol, isoeugenol, and dihydroeugenol is performed and the solution homopolymerization of these biobased monomers is studied. Moreover, aiming to prepare functional polymers, the introduction of epoxy and cyclic carbonate groups is executed via modification of the allylic double bond present in eugenol derived methacrylate. Thus, a novel platform of versatile biobased monomers derived from eugenol is presented, opening the opportunity to use them in a wide range of polymerization processes and application

Photochemical [2+2] Cycloaddition of Biobased Latexes for Composites with Microfibrillated Cellulose

A biobased latex was obtained by copolymerization in emulsion of ethoxy dihydroeugenyl methacrylate (EDMA) and coumarin methacrylate (CMA). Thin films of poly(EDMA-co-CMA) were irradiated with UV light at 365 nm, to promote the [2+2] photocycloaddition reaction of the coumarin moieties. The advancement of the reaction was followed by monitoring the intensity of the UV-Vis absorbance at 320 nm, characteristic of coumarin, after different irradiation times. Complete dimerization of the coumarin moieties could be achieved. A microfibrillated cellulose (MFC) reinforcement was added to the poly(EDMA-co-CMA) latexes to prepare composite materials. The permeability of the composite films to oxygen, before and after crosslinking, was assessed. For the non-crosslinked films, increasing the cellulose content from 5 wt% to 30 wt% decreased the oxygen transmission rate (OTR) by approximately 70%. When 1 wt% CMA moieties were present in the polymer backbone the OTR was approximately 50 % lower with respect to poly(EDMA) composites. A further slight decrease of permeability was observed upon crosslinking of the composite poly(EDMA-co-CMA)/MFC films

Radical aqueous emulsion copolymerization of eugenol-derived monomers for adhesive applications

International audienceBiobased monomers derived from eugenol were copolymerized by emulsion polymerization to produce latexes for adhesive applications. Stable latexes containing ethoxy dihydroeugenyl methacrylate and ethoxy eugenyl methacrylate with high total solids content of 50 wt% were obtained and characterized. Latexes synthesis was carried out using a semi-batch process and latexes with particle diameters in the range of 159-178 nm were successfully obtained. Glass transition temperature values of the resulting polymers ranged between -32 and -28°C. Furthermore, tack and peel measurements confirmed the possibility to use these latexes in adhesive applications

Photoinduced Polymerization of Eugenol-Derived Methacrylates

International audienc

Photoinduced Polymerization of Eugenol-Derived Methacrylates

International audienceBiobased monomers have been used to replace their petroleum counterparts in the synthesis of polymers that are aimed at different applications. However, environmentally friendly polymerization processes are also essential to guarantee greener materials. Thus, photoinduced polymerization, which is low-energy consuming and solvent-free, rises as a suitable option. In this work, eugenol-, isoeugenol-, and dihydroeugenol-derived methacrylates are employed in radical photopolymerization to produce biobased polymers. The polymerization is monitored in the absence and presence of a photoinitiator and under air or protected from air, using Real-Time Fourier Transform Infrared Spectroscopy. The polymerization rate of the methacrylate double bonds was affected by the presence and reactivity of the allyl and propenyl groups in the eugenol-and isoeugenol-derived methacrylates, respectively. These groups are involved in radical addition, degradative chain transfer, and termination reactions, yielding crosslinked polymers. The materials, in the form of films, are characterized by differential scanning calorimetry, thermogravimetric, and contact angle analyses

Gender differences and management of stroke risk of nonvalvular atrial fibrillation in an upper middle-income country: Insights from the CARMEN-AF registry

Background: Atrial Fibrillation (AF) is associated with an increased risk of stroke and systemic embolism. Several studies have suggested that female AF patients could have a greater risk for stroke. There is scarce information about clinical characteristics and use of antithrombotic therapies in Latin American patients with nonvalvular AF. Objective: To describe the gender differences in clinical characteristics, thromboembolic risk, and antithrombotic therapy of patients with nonvalvular AF recruited in Mexico, an upper middle-income country, into the prospective national CARMEN-AF Registry. Methods: A total of 1423 consecutive patients, with at least one thromboembolic risk factor were enrolled in CARMEN-AF Registry during a three-year period (2014–2017). They were categorized according to Gender. Results: Overall, 48.6% were women, mean age 70 ± 12 years. Diabetes, smoking, alcoholism, non-ischemic cardiomyopathy, coronary artery disease, and obstructive sleep apnea were higher in men. Most women were found with paroxysmal AF (40.6%), and most men with permanent AF (44.0%). No gender differences were found in the use of vitamin K antagonists (VKA) (30.5% in women vs. 28.0% in men). No gender differences were found in the use of direct oral anticoagulants (DOAC) (33.8% women vs 35.4% men). Conclusions: CARMEN-AF Registry demonstrates that in Mexico, regardless of gender, a large proportion of patients remain undertreated. No gender differences were found in the use of VKA or DOAC. Keywords: Atrial fibrillation, Gender, Thromboembolic risk, Antithrombotic therapy, Stroke, Mexic

Proceedings Of The 23Rd Paediatric Rheumatology European Society Congress: Part Two

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